function CrackGrow
global glb

a=glb.crack.length;
N=glb.crack.N;
dN=glb.crack.dN;
DK=glb.crack.KI;
C=glb.mater.C;
n=glb.mater.n;
p=glb.mater.p;
q=glb.mater.q;
type=glb.solver.grow;


switch type
    case{1,'paris'}
        da=dN*C*(DK).^n;
    case {2,'walker'}
        da=dN*C((1-R)^m*Kmax)^p;
    case {3,'forman'}
        da=C*DK^p/(Kc*(1-R)*DK);
    case {4,'closure'}
        da=C*(Kmax*(1-Cf)/(1-Cf0))^n;
end
a=a+da;
glb.crack.length=a;
glb.crack.da=da;
